The atom pencil: serial writing in the sub-micrometre domain

The atom pencil we describe here is a versatile tool that writes arbitrary structures by atomic deposition in a serial lithographic process. This device consists of a transversely laser-cooled and collimated cesium atomic beam that passes through a 4-pole atom-flux concentrator and impinges on to micron- and sub-micron-sized apertures. The aperture translates above a fixed substrate and enables the writing of sharp features with sizes down to 280 nm. We have investigated the writing and clogging properties of an atom pencil tip fabricated from silicon oxide pyramids perforated at the tip apex with a sub-micron aperture.

Secure architectures for pairing based public key cryptography

Along with the growing demand for cryptosystems in systems ranging from large servers to mobile devices, suitable cryptogrophic protocols for use under certain constraints are becoming more and more important. Constraints such as calculation time, area, efficiency and security, must be considered by the designer. Elliptic curves, since their introduction to public key cryptography in 1985 have challenged established public key and signature generation schemes such as RSA, offering more security per bit. Amongst Elliptic curve based systems, pairing based cryptographies are thoroughly researched and can be used in many public key protocols such as identity based schemes. For hardware implementions of pairing based protocols, all components which calculate operations over Elliptic curves can be considered. Designers of the pairing algorithms must choose calculation blocks and arrange the basic operations carefully so that the implementation can meet the constraints of time and hardware resource area. This thesis deals with different hardware architectures to accelerate the pairing based cryptosystems in the field of characteristic two. Using different top-level architectures the hardware efficiency of operations that run at different times is first considered in this thesis. Security is another important aspect of pairing based cryptography to be considered in practically Side Channel Analysis (SCA) attacks. The naively implemented hardware accelerators for pairing based cryptographies can be vulnerable when taking the physical analysis attacks into consideration. This thesis considered the weaknesses in pairing based public key cryptography and addresses the particular calculations in the systems that are insecure. In this case, countermeasures should be applied to protect the weak link of the implementation to improve and perfect the pairing based algorithms. Some important rules that the designers must obey to improve the security of the cryptosystems are proposed. According to these rules, three countermeasures that protect the pairing based cryptosystems against SCA attacks are applied. The implementations of the countermeasures are presented and their performances are investigated.

Scientism and instrumentalism After the Bomb: Dr Strangelove, End Zone, Crash and The Wire

This thesis argues that through the prism of America’s Cold War, scientism has emerged as the metanarrative of the postnuclear age. The advent of the bomb brought about a new primacy for mechanical and hyperrational thinking in the corridors of power not just in terms of managing the bomb itself but diffusing this ideology throughout the culture in social sciences, economics and other such institutional systems. The human need to mitigate or ameliorate against the chaos of the universe lies at the heart of not just religious faith but in the desire for perfect control. Thus there has been a transference of power from religious faith to the apparent material power of science and technology and the terra firma these supposedly objective means supply. The Cold War, however was a highly ideologically charged opposition between the two superpowers, and the scientific methodology that sprang forth to manage the Cold War and the bomb, in the United States, was not an objective scientific system divorced from the paranoia and dogma but a system that assumed a radically fundamentalist idea of capitalism. This is apparent in the widespread diffusion of game theory throughout Western postindustrial institutions. The inquiry of the thesis thus examines the texts that engage and criticise American Cold War methodology, beginning with the nuclear moment, so to speak, and Dr Strangelove’s incisive satire of moral abdication to machine processes. Moving on chronologically, the thesis examines the diffusion of particular kinds of masculinity and sexuality in postnuclear culture in Crash and End Zone and finishing up its analysis with the ethnographic portrayal of a modern American city in The Wire. More than anything else, the thesis wishes to reveal to what extent this technocratic consciousness puts pressure on language and on binding narratives.